Android15 框架层Java代码中的各种打印接口

叶羽西2026-01-06 9:30

1.WindowManagerService相关

使用ProtoLog接口打印

ProtoLog是Android系统内部使用的一种高性能日志机制，通过编译时优化和运行时控制来减少日志开销，适用于需要高性能的代码路径。ProtoLog日志接口具有高性能、结构化、可动态控制的特点，主要用于系统级组件（特别是系统服务和框架层）的调试日志，是对传统android.util.Log的增强和替代。

ProtoLog接口定义

Android15源代码中ProtoLog定义于frameworks/base/core/java/com/android/internal/protolog/ProtoLog.java，包名为com.android.internal.protoLog

java 复制代码

//打印接口
ProtoLog.d(IProtoLogGroup group, String messageString, Object... args)
ProtoLog.v(IProtoLogGroup group, String messageString, Object... args)
ProtoLog.i(IProtoLogGroup group, String messageString, Object... args)
ProtoLog.w(IProtoLogGroup group, String messageString, Object... args)
ProtoLog.e(IProtoLogGroup group, String messageString, Object... args)
ProtoLog.wtf(IProtoLogGroup group, String messageString, Object... args)

//使能控制
static boolean isEnabled(IProtoLogGroup group, LogLevel level)

//（单例）对象及初始化
static IProtoLog getSingleInstance()
static void init(IProtoLogGroup... groups)

ProtoLog接口使用

例如frameworks/base/services/core/java/com/android/server/wm/ActivityTaskSupervisor.java中，使用ProtoLog打印日志，

java 复制代码

boolean realStartActivityLocked(ActivityRecord r, WindowProcessController proc,
        boolean andResume, boolean checkConfig) throws RemoteException {
    if (!mRootWindowContainer.allPausedActivitiesComplete()) {
        // While there are activities pausing we skipping starting any new activities until
        // pauses are complete. NOTE: that we also do this for activities that are starting
        // in the paused state because they will first be resumed then paused on the client
        // side.
        ProtoLog.v(WM_DEBUG_STATES,
            "realStartActivityLocked: Skipping start of r=%s some activities pausing...",
            r);
        return false;
    }

    ...
}